 Good afternoon everyone. I am Shweta Yadav and today my topic of presentation is imaging in a patient with chronic lithium nephropathy. So, lithium salts are the mainstay of treatment of psychiatric disorder, majorly bipolar mood disorder. However, lithium has well-known pharmacological side effects and nephrotoxicity is one of the major adverse effects. About 20% of the patients on long-term lithium therapy can present with deranged serum creatinine and there is increased risk of progression to ESRD, which is end-stage renal disease. Lithium is one of the most common cause of nephrogenic diabetes in Cepidus and with rates of overt NDI being 12% in patients treated with lithium for 15 years and rates of lesser impairment such as polyuria or impaired renal concentrating ability seen in 19 and 54% respectively. The defect in urinary concentrating ability may be seen within 2-4 months after the initiation of therapy, but it becomes more prominent as duration of therapy progresses. Coming to imaging, ultrasound demonstrates mainly normal or decreased kidney volume slightly in increased cortical echogenicity and echogenic foci, which are distributed throughout renal parankaima, which may likely represent microsus that are below the resolution of ultrasound. Coming to cross-sectional imaging, MRI is more sensitive and compared to CT and T2 sequence of MRI can represent hyperintense foci, which are microsus distributed with heat, cortex and medulla of bilateral kidneys. CT has lower contrast resolution but more spatial resolution compared to MRI. But CT as such requires iodinated contrast agent, which increases the risk of contrast induced nephropathy in patients who is already having deranged serum creatinine. This ultrasound image depicts hyperaquid foci distributed within the renal parankaima, which are microsus below the resolution of ultrasound. And this T2 sequence of MRI represent microsus both in cortex and medulla and these are seen as hyperintense foci. Coming to our case report, there was a 60-year-old lady and she was having bipolar disorder. She was on lithium therapy for the past 20 years and now she was admitted in war with complaints of polyurea, polydipsy, and nocturia. Then lithium levels were done and lithium levels, the normal range of lithium level is 0.6 to 1.2 millimole per liter but this lady levels were 2.8 millimole per liter. Ultrasonic was done and kidneys were of normal size and punctate hyperaquid foci were seen on MRI, microsus, cortical and medullary multiples microsus were noted. Renal biopsy, although it is a global standard, was not done because in this patient, classical clinical history, presentation and radiological findings were enough to make the diagnosis of lithium nephropathy. Eventually, lithium was withdrawal and olenzapine was introduced as an alternative mood-stabilizing drug. Coming to discussion, lithium as such can cause focal interstitial nephritis and irreversible and progressive defect in urine-concentrating ability when taken chronically. Differential diagnosis, which should be considered for lithium-induced nephropathy includes simple renalysis, ADPKD or ARPKD medullary cystic kidney disease and long-term dialysis, which can be distinguished on the basis of number, location, size of cyst and clinical history. Lithium-induced nephropathy can be distinguished from glomerular cystic kidney disease as in glomerular cystic kidney disease, the cysts which are present are present only in cortex. It can be distinguished from ADPKD on the fact that in ADPKD the kidneys would be enlarged in size compared to lithium-induced nephropathy in which sizes of kidney would be normal or it might be reduced. Renal biopsy is core standard if there is a dilemma, but it is invasive in nature and there is a simple variability which is the limiting factor for renal biopsy and in our patient renal biopsy was not performed because of ethical reason. Conclusion, myelithym is the most efficacious drug for bipolar disorder. It is associated with significant toxicity, which is compounded by the need of patient with bipolar disorder to take chronic therapy to prevent relapse. MRI is highly effective as a diagnostic tool to demonstrate the morphological pattern of chronic lithium nephropathy and it can spare renal biopsy and in future it can also have a role in clinical management of patients treated with long-term lithium. So these are the references for my paper. Thank you and have a nice day.